ECM options

[Lil Blu]

I am running '87 5.0 H.O. (speed density) injection in my '73 Bronco on a 289 small block. I have heard that if I swith from a manual trans module to an auto trans module I should be able to pull a data stream for emissions diag. Can anyone confirm this, and if so does anyone know what p/n or code I need to look for. I imagine that a module for a MAF system would not work, but I do not know. Any help would be appreciated, thanks.

[SloSVO]

the HO computer doesn't let for data stream... you need the NON HO PCM for that.. also the injector firing order for the HO engine is different than the ignition firing order on the factory 289 firing order.. lil things that need to be addressed...

[Lil Blu]

That little thing has been addressed with a 351 cam. After changing the firing order for the injectors and running fine I found that the o2 sensors cause the ECM to bank fire the injectors only for the rich/lean cycle. Thuse I had a rich bank and a lean bank all the time that the ECM could not compensate for. So I installed the 351 cam and returned the injectors to thier stock location. Last year everything was clean as a new car. Somethings or things have failed sence then. This is why I need help. When I tested the MAP sensor it said I was about 1500 ft below sea level, this would certainly make the engine run a little rich. I replaced the MAP sensor and it improved a little all across the board, but I still have CO's about three times the allowance, while HC's are little high, they are not bad. This is why I am looking for way to get the data stream to see what is going on. If I install a non H.O. ECM, will this creat different problems as that would run the same firing order as the stock 289?

[SloSVO]

the HO fires the injectors in sequential order as the non fires them in batch form...how big is the cam you put in.. anything more than a stock type cam is a no good on speed density.. if anything you need to convert to Mass Air.. which entitles a mass air pcm and either a different harness or a repin at the 60 pin..

[Lil Blu]

The cam is small (maybe a 200/212), I chose one for more low rpm torque rather than high end h/p. The injectors may fire sequentially in some applications, just not when adjusting for the o2 input (this I can prove with a 4-gas anilizer and an isolated dual exhaust). Yes, I should have gone MASS air when I had the chance, but bad info at the time made me go this way, so I work with what I have.

[SloSVO]

good luck